Stackable communications system

ABSTRACT

A stackable communications apparatus comprises modules to be powered on in a sequence. Each of the modules comprises components that perform an individual function or group of functions of the apparatus, each module in the plurality of modules comprising an individual chassis stackable with at least another individual chassis of at least another module in the plurality of modules. The modules comprise at least two modules establishing surface contacts by stacking. The surface contacts maintain, without physical cabling, power connection between the at least two modules. A preceding module in the sequence determines, via a power controller in communication with a power controller of a next module, a power requirement of the next module. The power controller of the preceding module in the sequence enables power to the next module if a remaining power from the preceding module is greater than the power requirements of the next module.

CROSS-REFERENCE TO RELATED APPLICATIONS; PRIORITY CLAIM

This application claims benefit as a Continuation of application Ser.No. 12/393,025 filed on Feb. 25, 2009, which claims benefit of U.S.Provisional Application 61/031,312, filed Feb. 25, 2008, the entirecontents of which are hereby incorporated by reference as if fully setforth herein, under 35 U.S.C. § 119(e). The applicant hereby rescindsany disclaimer of claim scope in the parent application or theprosecution history thereof and advises the USPTO that the claims inthis application may be broader than any claim in the parentapplication.

FIELD OF THE INVENTION

The present invention generally relates to modular communicationssystems.

BACKGROUND

The approaches described in this section could be pursued, but are notnecessarily approaches that have been previously conceived or pursued.Therefore, unless otherwise indicated herein, the approaches describedin this section are not prior art to this application and are notadmitted to be prior art by inclusion in this section.

As digital technology has become an important part of many persons'lives, the need to deliver this technology in more innovative andconvenient ways has become more and more necessary. For example,televisions and methods to play content on televisions have encompassedmany innovative changes throughout the years. From cathode ray tubes todigital flat panel video displays, the video cassette recorder todigital video recorders, the changes in technologies have brought aboutmany changes to make viewing and playing content both more convenientand pleasing to the viewer. For example, wired connections made to atelevision set might be numerous and can easily lead to confusion forthe consumer. A typical television setup might now have twoHigh-Definition Multimedia Interface (“HDMI”) interface connectors inorder to connect a DVD player and a satellite receiver, severalcomponent cable connectors in order to connect high-definition devicessuch as a DVR recorder, RCA cable connectors to connect a video cassetterecorder, and RF connectors in order to connect an antenna or cablesignals. The number of different types of connections and wires mightlead to confusion and incorrect cabling by the user. At best, thenumerous wire connections are difficult to keep in order and theresulting mess of cables around the television set becomes an eyesore.Thus, more convenient and user-friendly solutions have become veryimportant as television technology, and the resulting new types of wiresand connections, becomes more advanced.

These changes and encompassing needs are not in any way limited to onlyto televisions but may be seen in many different technologies and venuessuch as, but not limited to, with telephone systems, entertainmentsystems, mobile communications, and computer systems. As technologychanges in general, there is a need to present the technology in waysmore convenient, user-friendly, and elegant to the user.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 is a diagram that illustrates examples of different modulestacking methods, according to an embodiment of the invention;

FIGS. 2A and 2B is a diagram that illustrates an example of connectionsmade in a typical topology of 10/100BASE-TX and the same connectionbeing made with close proximity inductively coupled wirelessconnections, according to an embodiment of the invention;

FIGS. 3A and 3B is a diagram that illustrates an example of connectionsmade in typical topology of 1000BASE-T and the same connection beingmade with close proximity inductively coupled wireless connections,according to an embodiment of the invention;

FIG. 4 is a picture that illustrates a separable coupling transformerfor use in close proximity inductively coupled wireless Ethernetpictured with the two halves of the transformer separated, according toan embodiment of the invention;

FIG. 5 is a picture that illustrates a separable coupling transformerfor use in close proximity inductively coupled wireless Ethernetpictured with the two halves of the transformer connected together,according to an embodiment of the invention;

FIG. 6 is a close-up picture that illustrates a separable couplingtransformer for use in close proximity inductively coupled wirelessEthernet, according to an embodiment of the invention;

FIG. 7 is a close-up picture that illustrates a separable couplingtransformer for use in close proximity inductively coupled wirelessEthernet implemented using C-shape cores, according to an embodiment ofthe invention;

FIG. 8 illustrates connection points on a module and an interior view ofthe module from a top view, according to an embodiment of the invention;

FIG. 9 illustrates a system used in conjunction with a televisionentertainment system, according to an embodiment of the invention;

FIG. 10 illustrates a reconfigurable audio system used in conjunctionwith a stackable communications system, according to an embodiment ofthe invention; and

FIG. 11 is a block diagram of a system on which embodiments of theinvention may be implemented.

DETAILED DESCRIPTION

An apparatus and methods in which to implement stackable and modularcommunications systems are described. In the following description, forthe purposes of explanation, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art that the presentinvention may be practiced without these specific details. In otherinstances, well-known structures and devices are shown in block diagramform in order to avoid unnecessarily obscuring the present invention.

Embodiments are described herein according to the following outline:

-   -   1.0 General Overview    -   2.0 Modular and Stackable Communications Systems        -   2.1 Interconnection between the Modules            -   2.1.1 Close Proximity Inductively Coupled Wireless                Ethernet Connections            -   2.1.2 Close Proximity Capacitive Coupled Wireless                Ethernet Connections            -   2.1.3 Optical Connections            -   2.1.4 Physical Connections            -   2.1.5 Close Proximity Connections Placement within a                Module and Network Topology within the set of Modules        -   2.2 Interconnection and Control of Power between Modules        -   2.3 Other Interconnection Configurations        -   2.4 Reconfigurable Audio System    -   3.0 Extensions and Alternatives    -   4.0 Implementation Mechanisms        1.0 General Overview

The needs identified in the foregoing Background, and other needs andobjects that will become apparent for the following description, areachieved in the present invention, which comprises different methods andapparatuses in which to implement modular and stackable communicationssystems.

As technology systems have become more and more sophisticated, theability to customize a system for an individual presents manypossibilities. In an embodiment, customizing a system for an individualis accomplished by modularizing particular features of the system. Forexample, in a television entertainment system, rather than providing asingle box that contains a digital video recorder, a cable televisiondecoder, a video cassette recorder, a sound processor, storageexpansion, and some other feature for a television, a manufacturer mightmodularize each of the features so that a user may purchase onlyfeatures that he or she wishes. In one example, a user might not haveany need for a cable television decoder as the user does not subscribeto the cable television service or is unable to obtain the service athis or her particular residence. In another example, a video cassetterecorder is not required as the user does not own any video cassettetapes. In an embodiment, a user purchases modules having particularfeatures that he or she wishes to use and combines the modules to createa personalized system. Modularizing negates the need to purchase a moreexpensive device that includes many features that the user may neveruse. In addition, the multi-featured device is often not upgradeable andnecessitates purchasing an entirely new device should the user wish afeature or technology that is developed a short time after purchase.

In addition, many traditional components, such as, but not limited to,DVR, cable set top, DVD player, IP set top, etc. have redundantfunctions that are common to each of the components. For example, morethan one component might include a power supply, MPEG decoder, videoscaler, video post processor, deinterlacer, or audio decoder, etc. In anembodiment, rather than duplicating each of these redundant features inseparate components, common functions are implemented once in anindividual module. The individual module may be a base module that iscommon to each stackable communications system or may be a module thathas a particular feature and requires another function in order tooperate correctly.

For example, a user might add modules to the stack such as a DVR tunerinput module, cable decoder tuner input section module, and/or DVD diskloader, etc. Under this circumstance, the modules send media contentdata, control signals, and configuration data through a high bandwidthnetwork backbone that interconnects the modules. With this system,display control and playback of content may be controlled using a singleremote control and user interface, simplifying the user experience.Redundancy is reduced and many video/audio cables may be eliminated tosimplify user setup. Modularizing also allows a user to upgradeparticular features of a system more efficiently and cheaply.

In another embodiment, the modular system may be applied to television,set-top boxes, or to one of the modules in a stackable communicationsystem. For example, a reconfigurable input/output panel may beimplemented on a television system. Small input/output modules might bestacked vertically on the back of a set top box module of a televisionto add additional input/output and/or networking capabilities.

Modularizing in order to create a system is not limited totelevision-related technologies but may be applied to any technologythat is capable of being modularized into different and separable parts.Some of these technologies may include, but are not limited to,telephone technologies, mobile entertainment technologies, computernetworks, computer technologies, etc.

2.0 Modular and Stackable Communications Systems

There are many ways in which to combine modularized features into asystem. In an embodiment, each module comprises a separate chassis, forexample, a rectangular box, with each module able to be stackedvertically on top of other modules. In this embodiment, each module hasidentical width and length dimensions so that each module may be stackedon any other module. The height of each module may vary depending uponthe technical feature of the module. In another embodiment, alldimensions of each module may be identical to all other modules. In yetanother embodiment, each module has a particular shape that whencombined with other modules, creates a new design. For example, eachsucceeding module that is placed higher than a particular module may besmaller in dimension than modules below the particular module such thatwhen placed together, a shape substantially similar to a pyramid isformed. In another embodiment, the shape and size of each module isdifferent but is configured in such a way as to enable each module to bestacked on any other module with close proximity. In this sense, themodule may take any type of shape or size, but each module must be ableto be correctly stacked and oriented with any other module.

In an embodiment, the order of the stacked modules does not matter andany module may be stacked on any other module. In another embodiment,modules are stacked in a particular order. Stacking the modules in aparticular order may be for a variety of reasons. For example, somemodules might be heavier and larger than others due to the featureoffered by the module. The largest module might be a DVR player with anextremely large hard drive in order to be able to store a large amountof content. Thus, in the stacking scheme, the DVR module would always beplaced in the bottom of the stack. Other modules may always be smallerand lighter and are hence placed higher in the vertical stack. Theactual size of the module and the placement of the module may vary fromimplementation to implementation. As another example, modules thatrequire more power might be located closer to the base module in orderto ensure that adequate power is received.

In an embodiment, each module is stacked horizontally next to othermodules substantially similar to how books are stacked next to eachother on a bookshelf. In an embodiment, the height of each modulestacked horizontally is substantially of equal size and the depth andwidth of each module may vary depending upon the feature presented bythe module. For example, a particular module may be constrained by theelectronics within the particular module and thus might need to bethicker than most other modules. In another embodiment, each modulestacked horizontally is not of equal size but is configured in shapesuch as to be able to place each module in approximately close proximityto other modules stacked horizontally. The external features of themodules may be designed to mimic actual books.

In another embodiment, modules are stacked horizontally and also placedhorizontally next to each other such that the side wall of each moduletouches the side wall of neighboring modules. In yet another embodiment,combinations of stacking configurations are used. For example, avertically stacked set of modules may be placed next to anothervertically stacked set of modules such that the side walls of one set ofmodules is flush with the side walls of the other set of modules. Thiscombination of vertical stacking and horizontal placement allowsinter-communication between all of the modules present. Each module hasthe capability to detect the orientation of any modules directlyconnected to it. This may be accomplished by the module detecting aconnection with another module via a bottom, side, top, or rear surfaceconnection.

FIG. 1 displays some possible embodiments of the stack of modules. Stack100 shows modules being stacked vertically on top of each other. Thisparticular stack shows that each module is of identical height and widthas other modules in the stack. Stack 102 is another vertical stack ofmodules, but this stack displays modules of varying height and width.Note that the depth may also vary for the stacks of modules and are notshown in the illustrations. Stack 104 displays a stack of modules placedhorizontally next to each other substantially similar to how books arestacked next to each other on a bookshelf. In the particular embodimentof stack 104, each of the modules has identical heights and widths.Stack 106 also shows modules placed horizontally next to each other butthe heights and widths of each of the modules vary. In stack 108,modules are placed in a horizontal configuration with other modules alsoplaced horizontally next to the module. Stack 110 displays two sets ofmodules stacked vertically on top of each other. One set of modules isplaced horizontally next to the other set of modules such that eachmodule may be in communication with all other modules.

In an embodiment, in order to ensure proper alignment of the modulesadjacent to one another, magnets are located at a particular point onthe module. When two adjacent modules are properly aligned, the magnetsare attracted to each other and maintain correct alignment of themodules. If the adjacent modules are incorrectly aligned, the magnetsrepel each other and do not allow the user to position the modules inthe incorrect position.

2.1 Interconnection Between the Modules

The modules are enabled to communicate data and power with otherconnected modules. In an embodiment, the presence of physical cabling iseliminated as much as possible between the modules. In all otherrespects, a high bandwidth data and power connection is maintainedbetween the modules.

In an embodiment, the modules are connected via Ethernet connection.Ethernet networks are a very robust and reliable data interconnectionmethod and are typically connected via twisted pair cables. Powertransmission may also be implemented over an Ethernet connection furtherlimiting the number of physical connections required between eachmodule. A twisted pair cable may be, for example, a Cat 5e unshieldedtwisted pair cable, however any type of connection cable may be usedthat transmits the signal from one connection to the other connection.

In a typical Ethernet connection using twisted pair cable, the cableconnects two devices together. Each end of the cable connects to a mediainterface connector. In each device, the media interface connector isassociated with an isolation transformer. A common mode choke also maybe present, depending upon the implementation. Both the isolationtransformer and common mode choke, if present, help maintain the signalacross the Ethernet network. Isolation transformers block transmissionof DC signals from one circuit to the other, but allow AC signals topass through. Common mode chokes reduce common mode noise from eitherbeing transmitted onto the cable connecting the devices and reducesnoise picked up on the cable from making its way to the receiver andtransmitter circuitry of the connected devices.

A transformer is a device that transfers electrical energy from onecircuit to another through inductively coupled electrical conductors.Inductive coupling refers to the transfer of energy from one circuitcomponent to another through a shared magnetic field. A change incurrent flow through the primary windings induces current flow in thesecondary windings. The two devices may be physically contained in asingle unit such as in the two sides of a transformer. The transformeris based on the principle that an electric current produces a magneticfield and that a changing magnetic field within a coil of wire induces avoltage across the ends of the coil, called electromagnetic induction.By changing the current in the primary coil, the strength of themagnetic field from the primary coil changes. Because the changingmagnetic field extends into the secondary coil, a voltage is inducedacross the secondary coil, thereby transmitting a signal. The signal inthe Ethernet connection travels from the media interface connector andthen through the isolation transformer and the common mode choke, ifpresent. The signal then travels to a communications chip that is ableto receive or transmit signals over the network.

2.1.1 Close Proximity Inductively Coupled Wireless Ethernet

In an embodiment, rather than using twisted pair cable in order toeffect the connection of the two separate devices, the media interfaceconnector is bypassed and a connection is formed via a separablecoupling transformer. The separable coupling transformer takes the placeof the isolation transformers in the Ethernet connected device. In anembodiment, the separable coupling transformer is broken into twohalves, where one half of the transformer is mounted in the side of eachdevice in the communications link. When the two halves of the separablecoupling transformer are placed in close proximity to each other, thetransformer is able to transmit signals from one module or device to theother module or device using electromagnetic induction. The signal maybe bi-directional between the modules. The ability of the isolationtransformer to isolate DC signals is maintained with the transformeremployed in the embodiment. However, the requirement for an isolationtransformer to isolate the electronics from large voltages induced onthe cable from lightning, electrical noise, etc. is not needed becausethe cable is no longer used.

In an embodiment, two close-proximity, inductively coupled connectionsare used to form a 10/100Base-TX connection. In another embodiment, fourclose-proximity, inductively coupled connections are used to form a1000BASE-T connection. The number of connections may vary depending uponthe networking standard used and the throughput sought in theconnection. In an embodiment, if there is more than one close-proximity,inductively coupled connection between modules, then theclose-proximity, inductively coupled connections are placed at a minimumdistance apart such that cross-induction between the connections aredecreased. Placing connections a minimum distance apart minimizes theprobability that a signal made by a close-proximity, inductively coupledconnection is impaired from cross-induction from adjoining inductivelycoupled connections.

An illustration of an Ethernet connection based upon 10/100Base-TXTopology that carries network traffic at the nominal rate of either 10Mbit/s or 100 Mbit/s and a wireless connection according to anembodiment of the invention and 10/100Base-TX Topology is shown in FIGS.2A and 2B. FIG. 2A illustrates the typical topology for a 10/100Base-TXconnection 200 using twisted pair cable from Station A 202 to Station B230. Going from left to right which is the flow of network traffic withthe connection located at the topmost of FIG. 2A, the transmitter 204 inStation A 202 is connected to an isolation transformer 206A and a commonmode choke (“CMC”) 208A. The CMC 208A is connected to the mediainterface connector 210A of Station A 202. A twisted pair cable 212Aconnects the media interface connector 210A of Station A 202 to themedia interface connector 232A of Station B 230. In Station B 230, themedia interface connector 232A is connected to the isolation transformer234A, the CMC 236A, and finally the receiver 238. The other connectionillustrated with Station A 202 and Station B 230 shows a connection withtraffic flow in the opposite direction with a transmitter 240 at StationB 230 and a receiver 214 at Station A 202. From the transmitter atStation B, the network traffic then flows to the isolation transformer234B, the CMC 236B, and then the media interface connector 232B ofStation B 230. After crossing the twisted pair media 212B, traffic flowsto Station A 202 first to the media interface connector 210B, theisolation transformer 206B, the CMC 208B, and finally the receiver 214.

FIG. 2B illustrates an Ethernet connection between Station A and StationB that displays a topology based on 10/100Base-TX that uses closeproximity inductively coupled wireless connections 250. As shown in FIG.2B, in place of the isolation transformer and twisted pair media that isseen in the traditional 10/100Base-TX topology, is a separable couplingtransformer that is aligned to connect Station A 252 and Station B 270.The media interface connector is no longer required in this connectionbut the CMC may still be present. Also, note that a connection is madefor each direction of data. Data moves from transmitter 253 in Station A252 to the CMC 254A and then the separable coupling transformer 256A ofStation A 252. The signal passes to the separable coupling transformer272A of station B 270, the CMC 274A, and finally the receiver 276. Forthe other connection shown in the lower section of the illustration,data transfers from the Station B 270 transmitter 278, then to the CMC274B, and then the separable coupling transformer 272B on the Station Bside. The data then passes to separable coupling transformer 256B ofStation A 252, to the CMC 254B and then the receiver 258.

An illustration of an Ethernet connection based upon 1000BASE-T Topologythat carries network traffic at the nominal rate of 1000 Mbit/s halfduplex and 2000 Mbit/s full duplex and a wireless connection accordingto an embodiment of the invention and 1000BASE-T Topology is shown inFIGS. 3A and 3B. FIG. 3A illustrates the typical topology for a1000BASE-T connection 300 using twisted pair cable from Station A 302 toStation B 320. The flow of network traffic is bi-directionally and maybe concurrent because, among other things, each station employs a hybridtransmitter receiver capable of both sending and receiving with echocancellation. Going from left to right, the hybrid transmitter/receiver304 in Station A 302 is connected to a CMC 306, and then an isolationtransformer 308. The isolation transformer 308 is connected to the mediainterface connector 310 of Station A 302. A twisted pair cable 312connects the media interface connector 310 of Station A 302 to the mediainterface connector 322 of Station B 320. In Station B 320, the mediainterface connector 322 is connected to the isolation transformer 324,the CMC 326, and finally the receiver 328. The other connections in FIG.3A are not illustrated with Station A and Station B but are merelyduplicated four times, one per twisted pair connection.

FIG. 3B illustrates an Ethernet connection between Station A and StationB that displays a topology based on 1000BASE-T topology that uses closeproximity inductively coupled wireless connections 350. As shown in FIG.3B, in place of the isolation transformer and twisted pair media thatare seen in the traditional 1000BASE-T topology, is a separable couplingtransformer that is aligned to connect Station A 352 and Station B 370.The media interface connector is no longer required in this connectionbut the CMC is still present. Also, note that there are four separateconnections made. Data moves from the hybrid transmitter/receiver 354 inStation A 352 to the CMC 356 and then the separable coupling transformer358 of Station A 352. The signal passes to the separable couplingtransformer 372 of station B 370, the CMC 374, and finally the hybridtransmitter/receiver 376. The other connections in FIG. 3B are notillustrated with Station A and Station B but are merely duplicated fourtimes.

A connection via a close-proximity inductively coupled transformer viaEthernet presents many advantages over existing radio frequency basedwireless connections such as Wi-Fi, ultra wideband, and any other radiofrequency wireless connections. First and foremost, using an Ethernetconnection allows one to leverage the existing infrastructure thatexists for Ethernet. For example, many devices already contain Ethernetbased networking chips and thus no further changes must be made to theEthernet signaling portion of the device other than modifications to thetransformer and elimination of physical media connectors. RFtechnologies such as Wi-Fi are also more expensive and presentdifficulties that may be encountered from interference of devices thatshare a similar frequency and additional regulations by the FCC.

In an embodiment, when the two sides of the separable couplingtransformer are placed in close proximity to each other in the correctorientation, the magnetic flux generated and transferred between thetransformers makes an inductive connection. The separable couplingtransformer is only able to create an inductive connection of a correctphase if the two halves of the transformer on each module are orientedcorrectly with respect to each other. The two transformer halves alsoneed to be within a certain distance from each other in order for themagnetic field to be efficiently coupled between transformer halves. Inan embodiment, the correct alignment and orientation is ensured byplacing magnets in each module or device so that when any two modules ordevices are stacked together or placed in close proximity to each other,the two modules are pulled tightly together minimizing the air gap andforced to be in the correct orientation. The north and south polls ofthe magnets are arranged such that the modules can only be stacked inthe correct orientation, otherwise the magnets repel.

In another embodiment, the correct alignment and orientation of themodules is ensured by placing a marker or design on each of the modulesor devices. The marker or design placed on the modules or device maycomprise two halves, for example a protrusion on one module and acorresponding indentation on another module or two halves of a logo.When the two modules are placed in correct orientation with each otherin order to complete the marker or design, the transformers in themodules are also in the correct orientation to create a wirelessEthernet connection. In another embodiment, an encompassing design isplaced across a number of devices or modules. When the devices ormodules are placed in the correct orientation, the design may becompleted across all of the devices or modules.

As used herein, the term “air gap” is defined as the amount of distancebetween the two separable coupling transformers located within themodules or devices that are stacked together. In an embodiment, the sizeof the air gap between the two connecting separable couplingtransformers is within a maximum limit that is allowable in order totransmit a signal of a specified quality between the separable couplingtransformers. In an embodiment, the size of the air gap may vary fromimplementation to implementation. The maximum permissible size of theair gap may vary due to a variety of factors, including, but not limitedto, the number of windings on the transformer, the size of theconductors used in the windings, the shape of the core used for theseparable coupling transformer, the core material used in the separablecoupling transformer, or any other factor that may affect the size ofthe air gap between the two halves of the separable couplingtransformer.

In an embodiment, the number of windings on each separable couplingtransformer half are symmetric. In another embodiment, the number ofwindings on each separable coupling transformer half are not symmetricand varies for each separable coupling transformer pair. In anembodiment, the shape of the core of the separable coupling transformermay vary, and can include, but may not be limited to, C-shaped,E-shaped, U-shaped, donut, or rectangular. In an embodiment, thematerials used in the separable coupling transformer may comprise anymaterial that allows inductive coupling, including, but not limited toferrite, powdered iron, cobalt, or nickel iron. In an embodiment, thenumber of windings on the separable coupling transformers may varydepending upon the shape and material used for the transformer. In anembodiment, the type and material of the separable coupling transformermay vary depending upon the power source of the transmitter being fromthe center tap of the transformer.

FIGS. 4-7 show actual pictures of working models of the transformersused in close proximity inductively coupled wireless Ethernet. FIG. 4illustrates a picture of the two separable coupling transformers thatmay be used for close proximity inductively coupled wireless Ethernetshown separately and not connected together. Element 400 shows one halfof the two separable coupling transformers and element 402 displays theother half. FIG. 5 illustrates a picture of the two separable couplingtransformers that may be used for close proximity inductively coupledwireless Ethernet shown held together. The two separable couplingtransformers 500 and 504 are shown held together. The paper held betweenthe two transformers displays the air gap 502. FIG. 6 illustrates apicture of the two separable coupling transformers 600 and 602 that maybe used for close proximity inductively coupled wireless Ethernet shownclose up. FIG. 7 illustrates a picture of the two separable couplingtransformers 700 and 702 that may be used for close proximityinductively coupled wireless Ethernet showing a close up of a C-shapedtransformer from a top view.

In an embodiment, in order to determine whether another module or devicemay be present with an adjacent transformer, the separable couplingtransformer in the device or module sends a signal pulse, or chirp. Thechirp is active whether or not an adjacent transformer is present andresults in a magnetic field emitted by the separable couplingtransformer. In an embodiment, to limit the radiated emissions caused bythe magnetic field, a small amount of paramagnetic material may beplaced next to the separable coupling transformer providing a returnflux path for the magnetic field emitted by the chip. The small amountof paramagnetic material may be ferrite, such as the material that maybe used to make a transformer, or any other material capable of actingas a return to the magnetic field emitted. In an embodiment, the smallamount of paramagnetic material is placed at a distance that is largerthan the air gap distance between the transformer halves. The increaseddistance ensures that the small amount of material does not affect thesignal sent between the adjacent modules.

In an embodiment, rather than sending a periodic signal to discover thepresents of adjacent transformers, the transmitting transformer isactivated in a module through another connection made between modules.For example, a power connection between modules might indicate that amodule has been placed next to another module, and that the transformershould be activated in order to create the close-proximity inductivelycoupled wireless Ethernet connection.

In an embodiment, using close-proximity, inductively coupledconnections, modules may also be connected to other devices. Rather thanonly being connected to other similar modules, devices, such as atelevision may be modified to also be able to connect to other devicesor modules using close-proximity, inductively coupled connections. Thetelevision might have a compartment or other area specially created toaccept modules so that a DVR or cable set top box may be connectedunobtrusively and conveniently.

2.1.2 Close Proximity Capacitive Coupled Wireless Connections

In an embodiment, close-proximity wireless connections are also madethrough capacitive coupled connections. For example, Serial AdvancedTechnology Attachment (“SATA”) connections use capacitive coupling toallow for the DC offset of signals. In capacitive coupling, a pair ofplates, with one plate in one module and another plate in anothermodule, are placed in close proximity in order to form a small capacitorthat is able to transmit high speed electrical signals from one moduleto the other module. A detailed description of capacitive coupledconnections may be found in “IBM Intelligent Bricks Project-Petabytesand Beyond” by W. W. Wilcke et al. (IBM Journal of Research andDevelopment, Vol. 50, No. 2/3, March/May 2006, pp. 181-197), that isincorporated herein by reference.

2.1.3 Optical Connections

Data may also be transferred between the modules using opticaltransmission, such as that used with optical audio data. In anembodiment, optical transmitters are placed in modules with an adjacentlight pipe. As long as the optical transmissions are correctly aligned(and allow a line of sight to transfer data from one module to anothermodule), an optical connection is made between adjacent modules. Inorder to connect multiple modules, light pipes are placed going both upand down the stack of modules.

2.1.4 Physical Connections

In an embodiment, physical connections connect adjacent modules in orderto allow data transmission between modules. Physical connections refersto any type of connection wherein a physical connection is made betweenmodules. For example, pogo pins may be used. Pogo pins refer to aslender cylinder containing spring-loaded pins. The spring loaded pinsconnect to another metallic connection point to secure a connectionbetween the two devices. Pogo pins may be seen, for example, in cellularphones where metallic contacts connect the battery to the cellularphone. Any other type of structure capable to performing a connectionbetween devices may also be used to effect a close-proximity physicalconnection.

2.1.5 Close Proximity Connections Placement within a Module and NetworkTopology within the Set of Modules

In an embodiment, close proximity connections are placed on each side ofa module. Thus, in a traditional rectangular or square module, therewould be a total of six separate connectors. The number of connectorsmay vary depending upon the shape of the module. This is shown in FIG.8. In FIG. 8, two views of a module are shown with close proximityconnections. In module 800, a three-dimensional illustration is shown ofthe front of a module. On each side of the module that is visible, closeproximity connections 802, 804, and 806 are present. The connections arein the interior of the module and thus are not visible from the outsideof the module. However, depending upon the implementation, the design ofthe module may be such that marks are made on the exterior of the moduleto display to users the placement of each close proximity connection.

In another embodiment, close proximity connections are placed only onparticular sides of a module. For example, modules may be designed toonly be stacked in a particular design, e.g. vertical stacking, etc, andthus connectors only need to be placed in locations where otherneighboring modules would be stacked.

In a set of modules, each node of the network starts and ends with eachadjacent module. Thus each module comprises a network switch or routerand this is shown in module 810. In module 810, a top-view illustrationis shown that shows the interior of a square module. In this particularembodiment, close-proximity connectors are shown as elements 814, 816,818, and 820 against each side of the module. Connecting eachclose-proximity connectors is element 812. Element 812 is a switch orrouter that makes the node of the network and controls the flow of datafrom the connection in one module to another module. For example, in thecase where three modules are stacked vertically on top of each other,the bottom module might wish to communicate with the top module. Underthis circumstance, the bottom module uses the switch and transfers datathrough the middle module to communicate with the top module.

In a set of modules, each module also has a unique IP address within thenetwork. In an embodiment, in order to efficiently allocate IP addressesfor the network to each of the modules, a base module of the set ofmodules has a DHCP server so that IP addresses are assigned to modulesdynamically. In an embodiment, IP addresses are assigned based upon thefunctionality of the particular module. In the circumstance where basemodules contain the DHCP server, each set of modules must contain a basemodule that has a DHCP server. By including the DHCP server within themodules themselves, there is no requirement that the modularcommunications system needs to be connected to a separate network. Inanother embodiment, the set of modules are connected to a network thathas a DHCP server. Thus, no base module with a DHCP server is necessary.Upon connection of a module to the network, the DHCP server assigns anIP address based upon the functionality of the module. This allows themodules to communicate with an existing home network.

In an embodiment, particular modules with a particular function containa DHCP server. In the circumstance where more than one module has a DHCPserver, then the modules with DHCP servers negotiate with each other inorder to determine which module with a DHCP server should assignaddresses.

In another embodiment, each module available to users are pre-assignedan IP address so that dynamic assignments are unnecessary. IP addressesmay be pre-assigned based on feature. For examples, a group of IPaddresses are reserved for modules that perform DVR functions, anothergroup of IP addresses are reserved for modules that perform cable-settop functions, etc. In the case where IP addresses are pre-assigned tomodules, the pre-assigned IP address may be later changed by anotherserver or the user in order to remove any IP address conflicts. Inanother embodiment, an arbitration occurs where IP collisions occurbecause of a conflict of IP addresses and the IP addresses are updatedand resolved to remove the conflict.

2.2 Interconnection and Control of Power Between the Modules

The modules are also interconnected to share power between each module.As one goal of modular design of the communications modules is to removeas much cabling as possible, a single power cable may be used to powerall of the modules connected.

In an embodiment, power management in the stack is implemented in adistributed fashion with replicated functions in each module. In anembodiment, each module within the stack contains a small (low power)controller chip, a power switch, and a few discrete components. The basemodule of the stack also includes components to determine the powerrating of an integrated power supply or external power brick (converterto a wall outlet) is connected to the base module.

In an embodiment, the power controller chip within each module has twoindependent serial links. One serial link communicates with the powercontroller in the module located above the module and another seriallink communicates with the power controller in the module located below.Either or both serial links may be disabled if a module is not presenteither above or below the module. In an embodiment, the power controlleris the master of the link to the module above and a slave to the modulebelow. In other embodiments, the power controller may be a slave to themodule above and a master to the module below. This is for horizontalalignments of stacks of modules. Master/slave configurations may also beimplemented left to right or right to left for horizontal configurationsof modules.

In yet other embodiments, particular modules are given preference to bethe master. For example, a module that performs a display function mightbe given priority over all other modules because the display function isparamount to the function of the entire set of modules. Under thiscircumstance, other modules might be given lower priorities. Thus,placement is not the determinant of which module is master and whichmodule is slave, but rather the priority assigned to the module is thedeterminant.

In order to control the amount to power that flows through the set ofmodules, the power required for each particular module should be knownand recorded. In an embodiment, each module transmits data that statesthe amount of power required for that particular module. Thisinformation may be transmitted by the module by any known datatransmission methods. The data transmission may be through physicalcontacts or pins that connect the modules together. In otherembodiments, magnets that are also used to align the modules properlymay be used to help transmit power, and power information betweenmodules.

In an embodiment, the power controller also detects when a particularmodule is installed or removed. Depending upon the implementation, thedetection may be limited to detecting when the module immediately abovethe particular module is installed or removed. In other implementations,the power controller is able to detect when any of the plurality of theset of modules has been removed and when a new module has beeninstalled.

In an example, a stack of modules is initially comprised of two modules,a base module “X” and a second module “Y.” A third module “Z” is thenadded to the stack of modules. Upon powering up of the base module, thepower controller chip of the base module “X” identifies the power brickthat connects to the wall outlet in order to determine the totalavailable power for the stack. The power controller chip of the basemodule “X” then reads a set of strapping pins to determine the powerrequired for the base. The controller subtracts the base power from thebrick power to find the remaining available power for all other moduleson the stack and stores the result.

The power controller chip in base module “X” then detects whether amodule is installed immediately above. In this particular case, themodule “Y” is located immediately above module “X”. A low voltage sourceis provided through the physical connection between modules “X,” “Y,”and “Z” (“XYZ interconnect”) to power just the power controller in the“Y” module, and does not power the entire module. The power controllerin module “X” then queries the power controller in module “Y” todetermine the power requirements of module “Y”. The power controller inmodule “Y” responds to the query by determining the module powerrequirements, such as by strapping pins, and then transmitting thatinformation back to module “X”.

The controller in module “X” subtracts the power required by the “Y”module from the remaining available power to the stack of modules. Ifthe result is greater then zero (and thus, adequate power is available)the controller in module “X” enables the power switch and supplies bulkpower to the “Y” module through the XYZ interconnect. The “X” powercontroller then writes the result into a register in the “Y” powercontroller, which is the remaining available power for all modulesstacked above module “Y.” Should not enough power be available for anadjacent module, the newly-installed module is not powered up and anerror is returned to the base module. This sequence continues up thestack, with each successive module determining the power needed by themodule above and powering the module only if sufficient power isavailable. This power-on method is inherently sequenced which reducesthe likelihood of power-on surges and reduces the cost of somecomponents in the modules.

When module “Z” is added to the stack, the “Y” power controller detectsthe new module and supplies low voltage power to the “Z” controller. The“Y” power controller then queries the “Z” power controller for the powerrequirements of module “Z.” The required power is subtracted from theremaining available power located with module “Y”. The “Y” controllerenables the power switch for module “Z” and then the remaining availablepower is stored in the “Z” power controller.

Different steps are taken upon removal of a module. If the “Z” module isremoved, then the “Y” power controller detects the start of the removalof the “Z” module before the power contacts disengage. The “Y” powercontroller disables the power switch for module “Z” and the energystored in the “Z” module's bulk power is dumped into a load before thepower contacts are broken, reducing the occurrence of any energy arcsacross the XYZ interconnect power contacts. Bulk power is thus, neverexposed on the XYZ interconnect, and the power supply may not beoverloaded with the addition of too many modules (since additionalmodules that overload the power supply do not power on) making the stacksafer.

By limiting communication to only connected modules next to each other,physical connections and the complexity of the stack of modules isreduced. Also, by each module storing the module's power requirementsand available power for other modules, other modules (or groups ofmodules) may be added or removed without affecting the power state ofexisting modules. This form of powering allows a system to be deployedthat does not have knowledge of future module power requirements andadds flexibility as an external brick power supply may be increased tosupport new modules without affecting existing modules power design.

In module detection, two contacts on the interconnection between modulesmay be used for communication between power controllers in adjacentmodules. One contact supplies low voltage (current limited) power fromthe lower model to the controller chip in the upper module. A secondcontact provides a point-to-point serial communications link that alsoserves as a detection mechanism when a module is added or removed.

The interconnection between modules may be a physical connection in theform of pogo pins. Pogo pins usually take the form of a slender cylindercontaining sharp, spring-loaded pins and a mating electricallyconductive surface. Pressed between two modules, the spring loaded pinsmake secure contact with mating conductive surfaces that provideelectrical connections between the two modules. For module detection,the two pogo pins that are used for controller chip power and the seriallink may be shorter then all other pogo pins. By making these pinsshorter, this ensures that the connection for controller power and theserial link make contact last when a module is added, and break contactfirst when a module is removed. The two pins may be located on oppositesides of the interconnection at a diagonal from each other.

In another embodiment, power is interconnected through the feet of eachof the modules. A connection is made at the top of the module where thefeet of an adjacent module are placed. The power connection, placed inthis way, appears wireless. The connection may be made of any materialthat is able to conduct power from one module to the next module, suchas, but not limited to, stainless steel or gold plated metals. In anembodiment, the connections themselves must have additional protectionsto avoid a short-circuit or safety hazards. This may include, but is notlimited to, physical protections such as a cover protecting theconnection area, or the application of power to contacts only when amodule has been detected to be adjacent.

In an embodiment, power is interconnected through a close proximityelectromagnetic induction. By removing entirely all aspects ofinterconnection visible from the outside of the module, the connectionstays protected and the possibility of a short-circuit is greatlyreduced.

2.3 Other Interconnection Configurations

In an embodiment, a network switch or router is placed in close distanceto where the modules are placed, such as on a table, bookshelf, etc.From the network switch or router, each component of a communicationssystem is interconnected with other components of a communicationssystem. An embodiment of this may be seen in FIG. 9. In FIG. 9, theentertainment system comprises a television set 902, modules 904 and906, and router 910. The router 910 connects the television set 902 andthe modules 904 and 906. In the diagram, a point-to-point connection isshown from the router 910 to each of the components. The router 910 hasa plurality of connections including connections 924, 926 and 928.Connection 928 from the router 910 is connected to the television set902 at connection 920 and the router 910 is also connected viaconnection 924 to modules 904 and 906 by connection 922. Connection 926at the router is free and not currently connected to any component inthe illustration. The router 910 is built and placed under the table butthe placement of the router 910 and any other component of the systemmay vary depending upon the preference of the user. Modules 904 and 906may be interconnected via any close-proximity connection to reducewiring and facilitate ease of setup.

In an embodiment, a common bus system may be used in a stackablecommunications system. Modules may be interconnected via any type ofconnection type, but the set of modules are connected to othercomponents, such as a television set, via a common bus. Components maybe placed anywhere along the common bus and more choices are availableto the user to place modules and components in a position more to his orher choosing. In order to efficiently manage the allocation of availabledata capacity on a network among devices connected to that network, anallocation system as described in U.S. Pat. Nos. 6,310,886 and 7,158,531B2, both owned by the Applicants and each of which are herebyincorporated by reference may be employed. In another embodiment, thecommon bus is built inside of a table. Each part of the entertainmentsystem is connected via the common bus that is built into the table. Onthe common bus are connection points to connect various components of asystem. The common bus interconnects each of the components of thesystem with modules being interconnected via any connection type.

The common bus is not limited to use with an entertainment center butmay also be used with any system that relies on communications such as,but not limited to a computer system, or mobile information devices. Forexample, to remove wires in a computer system, a common bus built intoor on a table might be used to connect a desktop or laptop computer to aseparate monitor or printer or any other peripheral device. Security isless of a concern since data is not sent in all directions like typicalRF devices, but limited to a close proximity. As such, storage devicessuch as additional hard drives or memory devices may also be placedsafely in the common bus system.

2.4 Reconfigurable Audio System

As the migration from analog to digital entertainment systems hasprogressed, one increasing problem of the digital living room is theaddition of more and more wired connections, especially in audiosystems. For example, in a surround sound system, speaker wires mightextend from the audio receiver to a center speaker, a subwoofer, sidespeakers, and rear speakers. This is in addition to the wires alreadyconnecting the entertainment system. To implement a whole audio systemthroughout the home, additional wires must be connecting audio systemsto speakers placed in each room. These wires multiply and ruin the decorof a room and increase complexity for installation of the system. Thesesame problems extend to other settings such as commercial theaters orconvention centers, educational settings such as in classrooms, or inany other location where a media system is installed.

In an embodiment, the stackable communication system has one or moreseparate audio servers that perform audio processing for the system. Asingle audio server may be implemented to perform all of the processingfor the home by processing audio for multiple rooms and outdoor audio.Multiple audio servers may be implemented in a home to add morecapabilities such as each server servicing a particular room or chainingtogether the servers for more processing power. Multiple audio serversalso are able to communicate with each other and to each module ordevice connected to the stackable communications system. The audioserver may be connected via a wire such as an HDMI cable, or any otherdata transferring wire. The audio server may also be connected via awireless connection to the rest of the stackable communication system.

In an embodiment, the audio server is part of a speaker bar. A speakerbar, as discussed herein, refers to a single component that is able toplay virtual surround sound without the need to use satellite speakers.The speaker bar comprises a single unit with multiple speakers that isusually placed near the display unit. The speaker bar is able toreplicate the different channels found on traditional surround soundsystems, such as front, rear, and side channels. The number of channelsmay vary depending upon the type of speaker bar employed.

In an embodiment, the speaker bar (and audio server) is wired to thebase module. In another embodiment, a separate wireless connection isused to connect the speaker bar to the stackable communications system.The audio server (whether or not located within the speaker bar) allowsa user to configure a speaker system in many different ways. Eachspeaker in the speaker system may also be referred to herein as a clientof the audio server. The speaker bar is connected to other audio deviceclients, such as speakers or any other device capable of playing audio,and is capable of configuring each client individually for the user. Inan embodiment, the type of speakers that are used with the speakersystem are of the same physical configuration. For example, the speakersmight have the same physical components such as the same number oftweeter speakers, midrange speakers, low end speakers, and electroniccomponents. Thus, no longer is a user required to purchase multipletypes of speaker, one type for side channel surround sound, and anothertype of speaker for the front channel of the surround sound. Rather, theaudio server is able to configure the speaker with the same physicalconfiguration to different functions. This saves the user from having topurchase many different types of speakers (that are also of limited use)and the same speakers may be used in different situations with no lossin audio quality. Other clients that may be connected to the audioserver may include, but is not limited to, digital picture frames (withspeakers), mp3 players, portable media devices, or any other device thatplays and/or processes audio.

In an embodiment, small optional modules are added to the audio serversimilar to the stackable communications system. For examples, a portablemedia player might be added that contains additional content or so thatcontent may be transferred to the media player. In another example,additional input/output connectors, wireless HDMI, or additionalwireless audio channels might be added to the base functionality of theaudio server.

The connection of the audio server to speaker clients may be made in avariety of methods. Some connections may be, but are not limited towireless, power line connections, wired, Bluetooth, and Wi-Fi. Thissystem of placing the audio server on a speaker bar offloads audioprocessing to a separate entity (rather than the base module) and mayallow more flexibility when installing the audio system. Speaker cablesare eliminated along with a separate audio receiver module.

In an embodiment, one set of speakers may be used to play stereo in aroom and a single speaker may be used to fill another room with ambientmusic. The soft configurations of a speaker changes for the particularpurpose to which the speaker is used. As used herein, a softconfiguration refers to any changes in the speaker configuration thatdoes not change the physical configuration of a speaker. This may referto, but is not limited to, adjusting the amount of range in a speaker,employing more high range than low range, disabling one of a pluralityof speakers in the speaker client, etc. The audio server may adjust thesoft configurations of a speaker client. For example, the softconfiguration for a speaker playing stereo (for example, the leftspeaker in a two-speaker setup), would be configured much differentlythan a single speaker setup that must play all media.

In an embodiment, the same physical configuration of speaker is usedthroughout a house, with each speaker client configured for a particularpurpose. The same physical configuration of speaker as the speakerclient allows users to purchase additional speakers easily and withoutfear that a speaker is limited to a single purpose. For example, theaudio server in the speaker bar detects speaker clients throughout thehome. Depending upon the speaker's placement in the home, the audioserver configures each speaker client for a particular purpose. Speakerclients in the rear of the room are configured to play rear sounds in asurround sound configuration. Speaker clients on the sides of the roomare also configured to play left and right sounds in a surround soundconfiguration. Speaker clients detected in other rooms of the housemight be configured to play simple stereo or have a setting to fill aroom with ambient music. Yet another speaker client detected that islocated in the backyard may be configured to play music outdoors as afull-range speaker. As another example, a speaker client used in oneroom as a surround speaker may be moved outdoors and reconfigured as afull-range speaker.

In another embodiment, a user may purchase different types of speakersthat are specialized for the wireless audio experience. For example,some speaker types that may be employed include, but are not limited to,a speaker bar, surround speakers, subwoofer, midrange, and tweeters. Theaudio server is able to detect the type of speaker or audio client andthen change the soft configuration of the speaker accordingly. Examplesof changes with the soft configuration may result in the audioprocessing performed by the audio server may change, the audioprocessing by the audio client may change, and/or the routing of theaudio within the client or the server may also change (e.g.reconfiguring how the amplifier drives the speakers). This type of setupis not as flexible but would present the user with the highest soundquality (as the type of speaker is manufactured for only a specificpurpose). Under this circumstance, the user is still able to configurethe speakers via the audio server. One change that the user may performis to configure the speakers based upon the type of media being played.For example, jazz music might require a different soft configuration foreach speaker than when an action movie is being played.

In an embodiment, speaker clients capable of detection by the audioserver may be implemented with an integrated wireless module embedded inthe speaker (or a device containing speakers). In another embodiment anexternal wireless module is connected to one or more traditional wiredspeakers (or devices containing speakers). The audio server is able todetect the type of speaker (or a profile is entered by the user) andthen alter the soft configuration of the speaker and audio systemaccordingly. Less flexible, special-purpose speakers (subwoofers, highrange speakers, etc.) may be intermixed with the speakers clientsdescribed as the same physical configuration speaker. For example, atypical installation might be to add one or more specialized wirelesssubwoofers throughout the house to extend the bass response, with allother speakers being a same physical configuration speaker configuredthroughout the home for a particular purpose such as left surround, rearsurround, or patio ambient. Over time, additional specialized speakersmay be installed such as a picture frame, with integrated speakers, forother specific uses.

The detection and configuration of speakers may occur in a variety ofmethods. In an embodiment, the audio server may continuously monitor forthe introduction of new speakers to the area. When a user comes homewith an additional speaker client, the audio server would automaticallydetect the discovery signal from the speaker client and then reconfigurethe speaker. In another embodiment, new speaker clients transmit amessage to any available audio server to announce that a new speaker isbeing added to the system. When the audio server detects that a newspeaker client is available, then the audio server would configure thespeaker for the system.

In an embodiment, when the audio server detects a new speaker client inthe system, the audio server prompts the user for additional informationon how to configure the speaker client. The audio server may employ agraphical user interface on a display device. The graphical userinterface may present the user with a variety of available softconfigurations to which the speaker may be configured. When the userselects a particular soft configuration, the audio server thenconfigures the speaker client according to the selection of the user. Inanother embodiment, the audio server prompts the user via voice or audioprompts. The user may respond orally or through any type of user commandinput.

In another embodiment, each speaker client contains an indicator thatindicates a particular soft configuration for the speaker client. Thisindicator may be a physical switch or pin that a user may manipulate tospecify the preferred soft configuration or location of the speakerclient. The indicator may also be a display screen on which a graphicaluser interface is presented to the user. The user may use any inputmethod (stylus, touch-screen, touchpad, keyboard, etc.) to indicate thepreferred soft configuration or location of the speaker client. Forexample, a user might indicate on the speaker client that the speaker isto be used as a rear channel surround sound speaker. Under thiscircumstance, the audio server would detect the speaker module and theindicated soft configuration on the switch. The audio server would thenre-configure the speaker client accordingly, and may perform additionalreconfigurations depending upon the type and genre of content that is tobe played.

In yet another embodiment, the audio server may detect a location of anewly installed speaker client, for example, via sound feedbackdetection or wireless detection. The location may be a relative locationwith respect to the audio server. Based upon the detected location, theaudio server determines the most probable use of the speaker andautomatically configures the speaker client according to that use. Theuser may also have the ability to override the selected use by the audioserver. For example, the audio server may detect a newly installedspeaker to the side left of the front speaker bar. Based upon thisinformation, the audio server determines that the speaker client is mostlikely a side left channel for surround sound and configures the speakeras such. When the speaker is later moved to another room, the audioserver detects the change in location and determines that the speaker islikely to be used for a standard stereo setup. A user may find that thesoft configuration determined is incorrect and override the audio serverand enter the correct soft configuration.

In another embodiment, multiple audio content streams may be provisionedby an audio server where multiple speaker client systems are configured.The multiple speaker client systems may be equal in number or more thanthe multiple audio content streams. Under this circumstance, thisenables the audio server to play the same music to multiple rooms. Theaudio server may also be able to synchronize content to the multiplerooms while provisioning a different content stream to another location.

Different types of clients may also be used in the audio setup. Becausewireless connections and detection is employed, other media clients suchas picture frames, video thin-client set top boxes, mp3 players, andconfigurable remote controls may be connected to the audio setup. Theseother clients may be used in a variety of ways. For example, the audioserver may detect the presence of an mp3 player in the vicinity. Contentfrom the mp3 player may be received by the audio server and then playedthroughout all of the speakers in the home, in a single room of thehome, or speakers located in the backyard. In another example, with theaddition of thin video client boxes, the DVR of the stackablecommunications system may be employed as a video server. Thin videoclient boxes might receive a transmission of content from a video serverand play the content on a display device. These thin video client boxesmay be located throughout a home and allow users to view content locatedon the video server. The audio server would then transmit theappropriate media to any speaker clients located near the thin videoclient box for the sound of the content.

FIG. 10 displays an example of a configurable audio system connected toa stackable communications system, according to an embodiment. In FIG.10, stackable communications system 1001 is located in the living roomand is connected via an HDMI wire to audio server 1003 that is part ofthe speaker bar located on the top of a television display device. Audioclients 1005 are located throughout the home and wirelessly connected toaudio server 1003. Audio server 1003 adjusts the soft configuration ofeach audio client 1005 based upon user input or the location of theaudio client. Audio clients 1005C is a surround sound system and mp3player located in the living room, audio clients 1005A is a set of twospeaker clients in another room of the home. Audio clients 1005B is asingle speaker and portable media device in yet another room. Pictureframe client 1023 is another audio client connected to the audio server1003 and represents an audio device that is capable of playing audio.Finally video server 1021 and video client 1011 are also connected tothe audio server 1003 with video server 1021 storing the content that istransmitted to video client 1011.

3.0 Extensions and Alternatives

In the foregoing specification, the invention has been described withreference to specific embodiments thereof. It will, however, be evidentthat various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of the invention. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense.

4.0 Implementation Mechanisms

According to one embodiment, the techniques described herein areimplemented by one or more special-purpose computing devices. Thespecial-purpose computing devices may be hard-wired to perform thetechniques, or may include digital electronic devices such as one ormore application-specific integrated circuits (ASICs) or fieldprogrammable gate arrays (FPGAs) that are persistently programmed toperform the techniques, or may include one or more general purposehardware processors programmed to perform the techniques pursuant toprogram instructions in firmware, memory, other storage, or acombination. Such special-purpose computing devices may also combinecustom hard-wired logic, ASICs, or FPGAs with custom programming toaccomplish the techniques. The special-purpose computing devices may bedesktop computer systems, portable computer systems, handheld devices,networking devices or any other device that incorporates hard-wiredand/or program logic to implement the techniques.

For example, FIG. 11 is a block diagram that illustrates a computersystem 1100 upon which an embodiment of the invention may beimplemented. Computer system 1100 includes a bus 1102 or othercommunication mechanism for communicating information, and a hardwareprocessor 1104 coupled with bus 1102 for processing information.Hardware processor 1104 may be, for example, a general purposemicroprocessor.

Computer system 1100 also includes a main memory 1106, such as a randomaccess memory (RAM) or other dynamic storage device, coupled to bus 1102for storing information and instructions to be executed by processor1104. Main memory 1106 also may be used for storing temporary variablesor other intermediate information during execution of instructions to beexecuted by processor 1104. Such instructions, when stored in storagemedia accessible to processor 1104, render computer system 1100 into aspecial-purpose machine that is customized to perform the operationsspecified in the instructions.

Computer system 1100 further includes a read only memory (ROM) 1108 orother static storage device coupled to bus 1102 for storing staticinformation and instructions for processor 1104. A storage device 1110,such as a magnetic disk or optical disk, is provided and coupled to bus1102 for storing information and instructions.

Computer system 1100 may be coupled via bus 1102 to a display 1112, suchas a cathode ray tube (CRT), for displaying information to a computeruser. An input device 1114, including alphanumeric and other keys, iscoupled to bus 1102 for communicating information and command selectionsto processor 1104. Another type of user input device is cursor control1116, such as a mouse, a trackball, or cursor direction keys forcommunicating direction information and command selections to processor1104 and for controlling cursor movement on display 1112. This inputdevice typically has two degrees of freedom in two axes, a first axis(e.g., x) and a second axis (e.g., y), that allows the device to specifypositions in a plane.

Computer system 1100 may implement the techniques described herein usingcustomized hard-wired logic, one or more ASICs or FPGAs, firmware and/orprogram logic which in combination with the computer system causes orprograms computer system 1100 to be a special-purpose machine. Accordingto one embodiment, the techniques herein are performed by computersystem 1100 in response to processor 1104 executing one or moresequences of one or more instructions contained in main memory 1106.Such instructions may be read into main memory 1106 from another storagemedium, such as storage device 1110. Execution of the sequences ofinstructions contained in main memory 1106 causes processor 1104 toperform the process steps described herein. In alternative embodiments,hard-wired circuitry may be used in place of or in combination withsoftware instructions.

The term “storage media” as used herein refers to any media that storedata and/or instructions that cause a machine to operation in a specificfashion. Such storage media may comprise non-volatile media and/orvolatile media. Non-volatile media includes, for example, optical ormagnetic disks, such as storage device 1110. Volatile media includesdynamic memory, such as main memory 1106. Common forms of storage mediainclude, for example, a floppy disk, a flexible disk, hard disk, solidstate drive, magnetic tape, or any other magnetic data storage medium, aCD-ROM, any other optical data storage medium, any physical medium withpatterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, NVRAM, anyother memory chip or cartridge.

Storage media is distinct from but may be used in conjunction withtransmission media. Transmission media participates in transferringinformation between storage media. For example, transmission mediaincludes coaxial cables, copper wire and fiber optics, including thewires that comprise bus 1102. Transmission media can also take the formof acoustic or light waves, such as those generated during radio-waveand infra-red data communications.

Various forms of media may be involved in carrying one or more sequencesof one or more instructions to processor 1104 for execution. Forexample, the instructions may initially be carried on a magnetic disk orsolid state drive of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to computer system 1100 canreceive the data on the telephone line and use an infra-red transmitterto convert the data to an infra-red signal. An infra-red detector canreceive the data carried in the infra-red signal and appropriatecircuitry can place the data on bus 1102. Bus 1102 carries the data tomain memory 1106, from which processor 1104 retrieves and executes theinstructions. The instructions received by main memory 1106 mayoptionally be stored on storage device 1110 either before or afterexecution by processor 1104.

Computer system 1100 also includes a communication interface 1118coupled to bus 1102. Communication interface 1118 provides a two-waydata communication coupling to a network link 1120 that is connected toa local network 1122. For example, communication interface 1118 may bean integrated services digital network (ISDN) card, cable modem,satellite modem, or a modem to provide a data communication connectionto a corresponding type of telephone line. As another example,communication interface 1118 may be a local area network (LAN) card toprovide a data communication connection to a compatible LAN. Wirelesslinks may also be implemented. In any such implementation, communicationinterface 1118 sends and receives electrical, electromagnetic or opticalsignals that carry digital data streams representing various types ofinformation.

Network link 1120 typically provides data communication through one ormore networks to other data devices. For example, network link 1120 mayprovide a connection through local network 1122 to a host computer 1124or to data equipment operated by an Internet Service Provider (ISP)1126. ISP 1126 in turn provides data communication services through theworld wide packet data communication network now commonly referred to asthe “Internet” 1128. Local network 1122 and Internet 1128 both useelectrical, electromagnetic or optical signals that carry digital datastreams. The signals through the various networks and the signals onnetwork link 1120 and through communication interface 1118, which carrythe digital data to and from computer system 1100, are example forms oftransmission media.

Computer system 1100 can send messages and receive data, includingprogram code, through the network(s), network link 1120 andcommunication interface 1118. In the Internet example, a server 1130might transmit a requested code for an application program throughInternet 1128, ISP 1126, local network 1122 and communication interface1118.

The received code may be executed by processor 1104 as it is received,and/or stored in storage device 1110, or other non-volatile storage forlater execution.

In the foregoing specification, embodiments of the invention have beendescribed with reference to numerous specific details that may vary fromimplementation to implementation. Thus, the sole and exclusive indicatorof what is the invention, and is intended by the applicants to be theinvention, is the set of claims that issue from this application, in thespecific form in which such claims issue, including any subsequentcorrection. Any definitions expressly set forth herein for termscontained in such claims shall govern the meaning of such terms as usedin the claims. Hence, no limitation, element, property, feature,advantage or attribute that is not expressly recited in a claim shouldlimit the scope of such claim in any way. The specification and drawingsare, accordingly, to be regarded in an illustrative rather than arestrictive sense.

What is claimed is:
 1. A stackable communications apparatus, comprising: a base module and a plurality of modules, wherein: the base module and the plurality of modules are physically stacked; the plurality of modules are powered on in a sequence defined by a priority level of each module in the plurality of modules; the base module receives power from a power source that is not one of the plurality of modules; the base module determines a total available power upon a powering on of the base module; and the base module determines a first module of the sequence and enables power to the first module; the base module and each module in the plurality of modules comprising components that perform an individual function or group of functions of the apparatus, the base module and each module in the plurality of modules comprising an individual chassis stackable with at least another individual chassis of at least another module in the plurality of modules; the base module and each module in the plurality of modules comprising surface contacts between adjacent modules by stacking, the surface contacts maintaining, without physical cabling and via at least one of an electrically conductive surface and a separable coupling transformer, at least one power connection between the base module and the plurality of modules; wherein each module in the plurality of modules determines, via a respective power controller that is communicating with a power controller of a next module in the sequence, a power requirement of the next module in the sequence; the respective power controller of each module in the plurality of modules enabling power to the next module in the sequence if a remaining part of the total available power unused by the module is determined by that module as greater than the power requirements of the next module in the sequence.
 2. The apparatus of claim 1, wherein the power connection is an inductive power connection via the separable coupling transformer.
 3. The apparatus of claim 1, wherein the module maintains close proximity inductively coupled Ethernet connections with the next module via the separable coupling transformer.
 4. The apparatus of claim 1, wherein the base module is configured to determine the total available power available from a power supply and compute a first remaining power available to other modules by subtracting power required by the base module from the total available power.
 5. The apparatus of claim 4, wherein the remaining power from the module is the first remaining power available to other modules, and wherein the module is configured to supply the first remaining power available to the next module.
 6. The apparatus of claim 1, wherein the power controller of the module is configured to determine the remaining power from the module.
 7. The apparatus of claim 6, wherein the remaining power from the module is determined by subtracting power required by the previous module from total power available to the module.
 8. The apparatus of claim 1, wherein the module is configured to detect a second module that is connected to the module.
 9. The apparatus of claim 8, wherein the module is configured to query the module that is connected for power requirements of the second module.
 10. The apparatus of claim 1, wherein the module and the next module are aligned in part via magnets.
 11. A method for powering on a base module and a plurality of modules in a sequence, wherein the plurality of modules are powered on in a sequence defined by a priority level of each module in the plurality of modules, the method comprising: establishing, between the base module and the plurality of modules, surface contacts by stacking, the surface contacts maintaining at least one power connection between the base module and the plurality of modules without physical cabling and via at least one of an electrically conductive surface and a separable coupling transformer; determining, by the base module, a total available power upon a powering on of the base module; determining, by each module in the plurality of modules via a respective power controller that is in communication with a power controller of a next module in the sequence, a power requirement of the next module; determining, by each module in the plurality of modules, via the respective power controller of each module, a remaining part of the total available power unused by that module; and in response to determining, via the respective power controller of each module in the sequence, that the remaining part of the total available power unused by that module is greater than the power requirements of the next module in the sequence, enabling, by the respective power controller of each module in the sequence, power to the next module in the sequence; wherein: the base module and the plurality of modules are physically stacked; the base module receives power from a power source that is not one of the plurality of modules; and the base module and each module in the plurality of modules performs an individual function or group of functions of the apparatus, the base module and each module in the plurality of modules comprising an individual chassis stackable with at least another individual chassis of at least another module in the plurality of modules.
 12. The method of claim 11, wherein the power connection is an inductive power connection via the separable coupling transformer.
 13. The method of claim 11, wherein the module maintains close proximity inductively coupled Ethernet connections with the next module via the separable coupling transformer.
 14. The method of claim 11, wherein the base module is configured to determine the total available power available from a power supply and compute a first remaining power available to other modules by subtracting power required by the base module from the total available power.
 15. The method of claim 14, wherein the remaining power from the module is the first remaining power available to other modules, and wherein the module is configured to supply the first remaining power available to the next module.
 16. The method of claim 11, wherein the power controller of the module is configured to determine the remaining power from the module.
 17. The method of claim 16, wherein the remaining power from the module is determined by subtracting power required by the previous module from total power available to the module.
 18. The method of claim 11, wherein the module is configured to detect a module that is connected to the module.
 19. The method of claim 18, wherein the module is configured to query the module that is connected for power requirements of the module.
 20. The method of claim 11, wherein the module and the next module are aligned in part via magnets. 